Impact of Total Laboratory Automation on Turnaround Times for Urine Cultures and Screening Specimens for MRSA, ESBL, and VRE Carriage: Retrospective Comparison With Manual Workflow.

Using computerized time-stamps, we compared the turnaround-times (TAT) for urine samples and screening ESwabs of MRSA, VRE, and ESBL carriage in the bacteriology laboratory of Geneva University Hospitals between January and December 2017 (period preceding the implementation of the WASPLabTM) with the same specimen types analyzed between January and December 2019 (period after the implementation of the automation). During both 1-year periods, a total of 98'380 specimens were analyzed (48'158 in 2017 vs. 50'222 in 2019). On the WASPLabTM, all culture plates were imaged at defined intervals each day of incubation, but the processing of the cultures (i.e., pathogen identification and antimicrobial susceptibility testing) was only performed during day shift hours (~8:00 A.M. to 4:30 P.M.). The median TAT for negative reports decreased by almost half for urine samples from 52.1 (2017) to 28.3 h (2019) (p < 0.001), and for MRSA screening specimens from 50.7 to 26.3 h (p < 0.001). The difference in median TAT for negative reports was less pronounced for screening of ESBL (50.2 vs. 43.0 h) (p < 0.001) and VRE (50.6 vs. 45.7 h) (p < 0.001). Despite a trend toward shorter result delivery for positive samples, there was no significant change in the median TAT. These results suggest that TAT for negative samples immediately benefit from automation, whereas TAT for positive samples also depend on the laboratory hours of operation and daily human resource management.

Second Periprosthetic Joint Infection Caused by Streptococcus dysgalactiae: How Genomic Sequencing Can Help Defining the Best Therapeutic Strategy.

Primary and revision arthroplasties are increasing worldwide, as are periprosthetic joint infections (PJI). The management of PJI requires surgery, the strategy of which is dictated by the acute or chronic nature of the infection, with an exchange of the implant in the event of a chronic PJI or in the case of recurrence with the same pathogen. We report the case of a 63-year-old man with two episodes of Streptococcus dysgalactiae subsp. equisimilis PJI within 9 months. Based on clinical suspicion of an haematogenous PJI, the patient was treated by DAIR (debridement, antibiotics, implant retention), while genomic sequencing revealed two different strains, confirming our hypothesis that no additional surgery was needed. Hence, we report a case where genomic analysis was decisive for the decision of the best therapeutic strategy.

Listeria monocytogenes infectious periaortitis: a case report from the infectious disease standpoint.

BACKGROUND: Endograft infection is a rare but extremely dangerous complication of aortic repair (25-100% of mortality). We describe here the first case of Listeria monocytogenes abdominal periaortitis associated with a vascular graft. We also discuss the differential diagnosis of periaortitis and provide a literature review of L. monocytogenes infectious aortitis. CASE PRESENTATION: Nine months after endovascular treatment of an abdominal aortic aneurysm (abdominal stent graft), a 76-year-old man was admitted for severe abdominal pain radiating to the back. Laboratory tests were normal apart from elevated C-reactive protein (CRP). Injected abdominal computed tomography (CT) showed infiltration of the fat tissues around the aortic endoprosthesis and aneurysmal sac expansion; positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) showed a hypermetabolic mass in contact with the endoprosthesis. Blood cultures were negative. At surgical revision, an infra-renal peri-aortic abscess was evident; post-operative antibiotic therapy with ciprofloxacin and doxycycline was started. Cultures of intraoperative samples were positive for L. monocytogenes. Results were further confirmed by a broad-range polymerase chain reaction (PCR) and next-generation sequencing. Antibiotic treatment was switched to intravenous amoxicillin for 6 weeks. Evolution was uneventful with decrease of inflammatory parameters and regression of the abscess. CONCLUSION: An etiologic bacterial diagnosis before starting antibiotic therapy is paramount; nevertheless, culture-independent methods may provide a microbiological diagnosis in those cases where antimicrobials are empirically used and when cultures remain negative.

Primary epiphyseal or apophyseal subacute osteomyelitis in the pediatric population: a report of fourteen cases and a systematic review of the literature.

BACKGROUND: Primary epiphyseal or apophyseal subacute osteomyelitis (PEASAO) is a rare condition that typically has mild symptoms and lack of a systemic reaction, according to opinions, case reports, and case series. We reviewed fourteen consecutive cases of PEASAO treated at our institution over a thirteen-year period to characterize this disorder. METHODS: We retrospectively reviewed the medical records of all children and adolescents who had been surgically managed for PEASAO at our institution from January 2000 to December 2012. A systematic review of the literature was also performed to identify trends in causative organisms and formulate evidence-based recommendations for diagnosis and treatment. RESULTS: Fourteen children (median age, 27.8 months) with PEASAO were included in the study. Fever (rectal temperature, >38°C) was present at admission in two children, C-reactive protein was within the normal range (<10 mg/dL) in eleven, the erythrocyte sedimentation rate was >20 mm/hr in eight, and the white blood-cell count was normal in all. The pathogen was not identified on blood cultures in any child and was identified on classical cultures of bone samples in only one. Use of PCR (polymerase chain reaction) assays allowed the pathogen to be identified in an additional eight children. The pathogen was Kingella kingae in eight and methicillin-sensitive Staphylococcus aureus in one. DISCUSSION: The use of organism-specific real-time PCR assays markedly improves the detection rate of the pathogen responsible for PEASAO, and K. kingae is the most commonly detected pathogen. The literature highlights a biphasic age distribution of PEASAO in children. The infantile form affects children from one to less than four years of age, accounting for approximately 75% of all PEASAO cases. The second form, in older children, is more likely to be associated with fever and systemic symptoms. The femur and the tibia are the most commonly affected long bones. Laboratory data are usually noncontributory for diagnosing PEASAO, and blood cultures are often sterile. Although K. kingae is the most commonly detected microorganism in children less than four years of age, S. aureus is responsible for most PEASAO in older children. Antibiotic treatment is usually sufficient to eradicate the pathogen.